The present invention relates to polyorganosiloxane compounds, and more particularly to polyorganosiloxane compounds which give a gellike substance capable of indicating the state of curing by change of color and having excellent adhesion to substrates such as plastics, metal, etc.
Conventionally, compositions which are curable to a gelllike polyorganosiloxane have been widely used, for example, for potting in manufacturing electric or electronic apparatus, for encapsulation or as an embedding material in surgical operations, by virtue of such a nature. (Refer to Japanese Patent Publication No. 17847/1973).
Such compositions do not harden as completely as, for example, a thermosetting resin does, but retain a gellike state with high adhesiveness even after completion of the curing reaction. Accordingly, in measuring the curing state of such a substance, it was impossible to measure the curing state through finger touch, which is the ordinary method for measuring the curing state. Therefore, there has conventionally been employed a method of measuring curing by means of cone penetration test.
However, it is not only extremely difficult but inefficient to conduct a penetration test to evaluate the curing state every time it is required in actual manufacturing processes. Therefore, evaluation of the curing state largely depends on the experience of operators present, thereby causing various problems such as breakage and failure of the gel due to their misjudgment of the curing state and further causing lowering of working efficiency, etc.